Reduction and catalytic behaviour of heterobimetallic copper-lanthanide oxides

The reduction of the heterobimetallic copper-lanthanide oxides 2CuO center dot CeO2 and 3CuO center dot Ln(2)CuO(4) (Ln=La, Pr, Nd) was studied by H-2-TG/DTA and H-2-TPR. A:l systems exhibit two main reduction steps accompanied by mass losses in the temperature range 20-1000 degrees C. The first step was attributed tc CuO reduction, whereas the second step is due either to copper reduction in the Ln(2)CuO(4) phase with the concomitant formation of Ln(2)O(3) or to the surface reduction of CeO2. The products were characterized by XRD, SEM, EDX, and BET techniques and are better described as supported copper type materials. They were active for the mesityl oxide (4-methyl-2-penten-2-one) gas phase hydrogenation. (C) 2007 Elsevier B.V. All rights reserved.